About animals

What does aquarium fish get sick


  • Due to pathogens (bacteria, fungi, flatworms, viruses, filamentous worms, protozoa, acanthosephalus, and others).
  • Not caused by pathogens (diseases of physical and chemical origin, as well as provoked by improper feeding).

The maintenance of aquarium fish plays a huge role in their life. With improper care, parasites can enter the aquarium, which will provoke the disease in the aquarium resident. The development of the disease can also be promoted by a new fish, poor-quality food, which contains the virus, and even aquarium plants.

To maintain health and protect aquarium fish from disease, adhere to the following rules:

  • Buy plants and fish only from trusted sellers. They must have certificates and permits for the sale of certain types of fish.
  • If there are different types of fish in your aquarium, read about their compatibility, they must have identical conditions, otherwise one of the species will die.
  • Before buying plants or a new fish, be sure to withstand isolation.

Diagnosis of fish diseases

First of all, you need to understand whether this is an external or internal disease. External manifest in the form of spots or growths on the fins and skin. Such diseases are easily noticed at an early stage and timely treatment is applied. Internal diseases of aquarium fish become noticeable only with careful observation. If any deviations are noticed in the behavior, the fish must be isolated from the others and continued observation. So you will not let the rest of the inhabitants of the aquarium get infected.

How to diagnose a disease

  • How has the behavior of the fish changed?
  • What has changed in the habitat before infection, perhaps new neighbors or algae have become a source of infection?
  • Did the temperature of the water in the aquarium change?
  • Was there an emission of harmful substances near the aquarium?
  • Pay attention to the food, especially if you have not used food of this brand before.
  • Did the pH change? An acid or alkaline disease may be triggered.

And these are not all the factors that can harm aquarium fish. The maintenance of aquarium fish directly affects their health and appearance. Once the source of the disease is identified, determine whether it is contagious or not. If the symptoms indicate that the disease is not contagious and does not threaten other inhabitants, then you only treat diseased fish. Otherwise, all aquatic animals are treated. The procedure is carried out in a separate quarantine aquarium, and the main one is thoroughly washed and disinfected.

Signs of illness

  • Behavior changes. Fish begin to swim in an unusual way: on their side, upside down or tail, swaying in place or rubbing against stones and other surfaces.
  • Subtle changes. Loss of appetite, discoloration, lethargy, apathy, etc. All this portends diseases of aquarium fish.
  • External signs. White dots, spots or ulcers appear on the fins and body. Around the mouth can be observed white "fluff", the fins and tail are gradually destroyed. The scales on the body are disheveled, and the belly is inflated.

Symptoms may occur separately or in combination. If at least one of the listed symptoms has been noticed, observe the fish more closely, and it is better to place it in a quarantine aquarium.

Aquarium for the treatment and prevention of diseases

Using an additional aquarium as an infirmary has several functions:

  • To monitor a sick fish, as well as for its treatment and recovery.
  • To relax the fish after stress, aggression, etc.
  • Short-term isolation for treatment with a medicinal product.
  • Isolation of fish for laying eggs, etc.

All newly acquired aquarium fish undergo preventive treatment. Diseases and treatment of ailments in other inhabitants of the aquarium due to this procedure will not bother you.

First aid kit

The following drugs are included in the list of necessary medicines:

  • Sea salt.
  • Methylene blue can cure bacterial and fungal infections. For external use only. Used only in a quarantine aquarium.
  • Mercurochrome or other disinfectants. It is used for injuries, fin rot or as a prophylactic for fungal infections.

If the aquarist does not have quick access to a veterinary pharmacy, the list of necessary tools can be supplemented: filter fillers, test kits for measuring the pH level, nitrate and ammonia content in water, and conditioning agents for water.

Drug administration

Four main methods of drug administration are used to treat aquarium fish.

Bath treatment. This is one of the common methods. The method of administering drugs through water is used to treat external and internal diseases. Treatment may be long-term or short-term. In the first type of treatment, the procedure is carried out in a common aquarium. Short-term treatment is carried out in a separate aquarium, where the stay of the fish is calculated in hours or minutes.

For the treatment of localized diseases, a local method is used. The fish is removed from the aquarium and the drug is applied to the affected area of ​​the body. In this way, injuries and other external diseases are mainly treated.

Internal medication. Usually, the medicine enters the fish with food. Thus, they fight endoparasites and systemic diseases.

And the last method is injections. Antibiotics and other drugs to treat systemic diseases are injected. This procedure is carried out by large fish and only a specialized doctor. Trying to introduce the drug yourself, you will only harm your pet.

Aquarium and equipment disinfection

For disinfection, it is necessary to carry out processing not only of the aquarium, but also of all the equipment that was contained inside or used in the treatment, it is better to replace the plants.

To get started, clean the aquarium. In any pet store you can purchase a disinfectant based on alcohols, detergents, phenol, etc. Having carefully treated the surfaces with such a solution, we rinse the aquarium with running water to get rid of toxic substances. The same procedure is done with aquarium equipment.

Disease prevention

Any disease is better to prevent than to cure. If you follow a few recommendations, you can forget about the diseases of aquarium fish for a long time.

  • Replace 1/10 of the water in the aquarium with a new one weekly.
  • Clean the soil weekly from rotted particles of plants, uneaten food and waste products of the inhabitants of the aquarium.
  • Keep track of the population density of the aquarium.
  • Use only high-quality feed, observing storage conditions.
  • Monitor the temperature, etc.

These simple recommendations will extend the life of your goldfish, pecilia, swordsmen, zebrafish and guppies.

Aquarium fish will help balance your psycho-emotional state and have a beneficial effect on the human psyche. In addition, they are silent and unpretentious.

Classification of diseases

Diseases of aquarium fish caused by pathogens:

Diseases that are not caused by pathogens:

  1. Physical etiology.
  2. Chemical etiology.
  3. Diseases as a result of improper diet and quality of feeding.

Conditionally, they can be divided into the following:

  1. Caused by pathogens:
    • Bacteria
    • Fungi
    • The simplest
    • Intestinal,
    • Flatworms
    • Acanthocephalus,
    • Viruses
    • Crustaceans
    • Filament helminths
  2. Not caused by pathogens:
    • Chemical etiology (poisoning with toxic substances),
    • Physical etiology (due to improper fish care - poor quality of the aquatic environment, violated temperature conditions),
    • The result of improper feeding (bloating, food poisoning).

How to avoid illness? Symptoms

Invasive diseases caused by viruses, bacteria, fungi, parasites enter the aquarium from various sources. This may be a new fish, live or frozen food, soil, scenery, plants. Infections can be avoided by observing a number of rules:

  1. Buy fish, plants, soil and decor only at trusted points of sale.
  2. After the purchase, the fish should be quarantined for 2-4 weeks, and the plants processed.

  • Observe the correct content parameters that are needed for different types of fish and plants.
  • Be observant - so you can timely detect signs of the disease at an early stage.
  • Common symptoms of diseases in aquarium fish, their diagnosis:

    1. Changes in appearance are observed: uncharacteristic white dots, spots, plaque, “fluff” may appear on their body. Also, sick fish can have ulcers, hemorrhages, increased mucus secretion. The fins collapse, stick together, fall away. The scales ruffle and fall off, the abdomen swells, the eyes bulge.
    2. The behavior of the fish is changing. Their head and tail lean down. They can swim belly up, or on their sides, swim on the surface, trapping air. Sick fish swim in jerks, rubbing against hard surfaces in the aquarium.
    3. Sick pets lose their appetite, become lethargic. They move unnaturally, the color of the body changes, it fades.

    Sometimes it happens that the diagnosis of the disease becomes a laborious affair. If you can not determine the disease, contact an ichthyopathologist, let the fish take a scraping from the fins and scales. The results of laboratory tests will tell you for sure what she is sick with.

    Different pathogens can cause similar symptoms, or infect fish with several diseases at the same time. For example, a pet infected with parasitic infestations may be attacked by bacteria or viruses. If he becomes ill, immediately diagnose to begin treatment at an early stage. With care and observation, you can save the life of your favorites. Timely treatment and correctly selected medications will help increase the likelihood of a full recovery of the fish.

    What is needed for disease prevention?

    The treatment of diseases is more difficult than their prevention. There are a number of simple rules, compliance with which will get rid of health problems of domestic fish:

      Replace 20-30% of the aquarium water regularly with clean and infused water (once every 7 days).

    Watch a video about water changes.

  • Clean the soil every week with a siphon funnel. Remove rotten food, plant residues, and fish waste products.
  • Avoid overcrowding in the tank. A medium-sized fish should account for 40-50 liters of water. This applies to cichlids, scalars, medium catfish, gourami, pecilieva.
  • Give your pets quality feed. Store it in the correct conditions according to the instructions.
  • Follow the correct feeding schedule: 1-2 times a day in small portions. Once every 7 days you can arrange a fasting day.

  • Observe the permissible temperature regime of water, do not allow a sharp change in temperature.
  • Keep your newly purchased fish in a quarantine tank for 2-4 weeks.
  • Use soft containers to transport the fish so that it is not frightened or injured.
  • When treating a pet, adhere to the instructions for use of the medicine, dose carefully, following all the rules.
  • Do not place soil or decorations in the aquarium that may injure the fish or are painted. They can release toxins into the water that poison everything living.
  • The aquarium cover must be such that the fish do not hit it hard and cannot jump out of the tank.
  • Nets, hoses, siphons, gauze fabrics should be different for each tank. After using the equipment in an aquarium with sick fish, it must be treated with disinfectant solutions.
  • Disease caused by infection

    Plistiforosis, or neon disease - the causative agent is a fungus of the genus Plistiphora hyphessobryconis, which settles in the muscle tissue of fish. Most neon diseases are affected. Signs of the disease at an early stage: the luminous neon strip dims, later completely fades. In other fish, the color of the scales fades. Today, there are no effective ways of treating patients with pleistiforosis.

    Columnariosis - the causative agent of infection is the rod-shaped bacterium Flexibacter columnaris. Signs: a sick fish is externally covered with white “cotton wool”, especially in the mouth, which is why the disease is also called “oral fungus”. Treatment is with phenoxyethanol in a quarantine jail. It is also effective to use baths with Merbromin or methylene blue. Antibiotics can be used if the disease has led to damage to the internal tissues.

    Branchiomycosis is a fungal infection that affects the gills of fish. The causative agent of the disease is Branchiomyces demigrans and Branchiomyces sanguinis. It is necessary to treat branchiomycosis with the use of fungicidal medicines, which are added to quarantine jails. You should take tests from the fish. After the diagnosis is established, it is necessary to remove the remains of feed and waste products from the general aquarium. It is necessary to clean the soil, and make the replacement of half the volume of aquarium water, include powerful aeration.

    Saprolegniosis is an infection caused by fungi of the genus Saprolegnia. Treatment is carried out using antifungal drugs (diluted streptocide). In a separate container, you need to carry out baths for sick fish, using a solution of sodium chloride 5%. Effective in the fight against fungi, copper sulfate, hydrochloride, rivanol, formalin. If the fungus has a localization site on the damaged area of ​​the skin, then it is better to place the fish in the depot, and use a solution of malachite green oxalate for treatment to remove the source of infection.

    Tuberculosis of fish is a terrible disease that appears due to the bacteria Mycobacterium piscium. Under the microscope, it has the shape of a fixed stick. When a bacterium enters the aquarium, several fish can pick it up. Sensitive to this infection are representatives of characins, cyprinids, labyrinths, and tropical cyprinids. Less commonly, tuberculosis is found in cichlids, pecilia, and cetrarch. Mycobacterium piscium is resistant to acid, and can develop at a temperature of 18-25 degrees Celsius. Fish should be treated after the first symptoms are detected. In the early stages, when pets are still eating, kanamycin should be used, which must be added to the feed. Dose: 10 mg per 10 grams of feed. At the next stages of tuberculosis, the fish are not treated, they are destroyed, and the aquarium is completely processed.

    Invasive diseases

    Hexamitosis - the causative agent of the disease is a drop-shaped parasitic flagellate. It enters the gallbladder or intestines of the fish, where the disease begins to develop. Symptoms: the fish refuses food, ulcers, or holes form on the body. Patients should immediately be quarantined. In American and African cichlids, hexamitosis is less common.

    See how to treat hexamitosis in aquarium fish.

    In the aquarium, you should increase the temperature of the water to 33-35 o C, which has a detrimental effect on parasites. The increase in the temperature range should take place gradually, for example, by 3-4 ° C in 24 hours. At this time, it is better for the fish not to give food. Hexamitosis can be defeated using the drug metronidazole.It is more gentle, and does not affect biological filtration. The medicine must be added to the general aquarium without transferring unhealthy pets to quarantine. Dose: 250 mg per 35 liters of water. It is necessary to add medicine for three days, while replacing 25% of aquarium water. Later, in a day, 15% of water can be replaced. If, during treatment, the fish refuse food, it must be suspended. After 7 days, the first improvements will be noticeable, but in order not to relapse, treatment is not recommended to be discontinued, because its recommended period: 12-15 days.

    Kostiosis is an invasive disease that appears with a unicellular parasite of the genus Costianecatrix. It is brought into an aquarium with live food, sick fish. The first symptoms: the fish rubs about the scenery, then the gills begin to become covered with mucus, due to which respiratory arrest can occur. Fish have no appetite, refuse to feed. In the later stages, the body is covered with bluish-gray dots, or plaque. It is possible to treat boneosis with the use of such means:

    • Potassium permanganate. Dose: 0.1 grams per 1 liter of water. In the bath, fish should be dipped for 40-50 minutes. Repeat for 5 days.
    • Copper sulfate: 1 gram per 10 liters of water. Place the fish in the solution for 20 minutes. Repeat for 5 days.
    • Salt: 1 tablespoon (25 grams) per 10 liters of water. Keep the fish in the bath for 15 minutes. Repeat for 7 days. Salt solution is not suitable for all types of fish, this must be taken into account during medical procedures.

    Diagnosis of diseases in aquarium fish. Symptoms

    The owner of the aquarium needs to know that it is easier to save fish from disease than to cure it. By following this rule, danger can be avoided, but pathologies must be recognized. They are called:

    • bacteria
    • fungi
    • simple ciliates or crustaceans,
    • viruses
    • flatworms from the flukes category.

    A huge number of signs of ill health are known, and for each disease they are different. Correctly executed and timely actions of the fish owner contribute to recovery. It is impractical to run pathologies.


    Ichthyophthyroidism, or as it is often called "decoy", due to the characteristic white dots on the scales of the fish, similar to semolina. Have infected ciliates ichthyophthirius fish shrink the body and fins, mostly the caudal. The body is weakened, her behavior is sluggish, she rubs on the ground. Movement occurs jerkily.

    Fish tuberculosis, exhaustion

    Symptoms are blood-drenched parts of the body, dark spots, lack of desire for food, low weight and a tumbled stomach. The disease is not cured.

    Often leads to dropsy. The scales of the fish are ruffled, the eyes bulge, the stomach increases in size. The twisted fish is on the ground. It is impossible to cure the disease.

    Treatment recommendations

    The first thing to do with any disease, whether it is the most common bacterial infection or parasitic - salt water. Salt (small table) kills the infection, but is completely safe for all the inhabitants of the aquarium. It should be filled in proportion - 1 tablespoon for every 10 liters of water. Those. if you have an aquarium for 100 liters, you should fill up 10 tablespoons.

    Second - any illumination for sick fish is harmful. Sick fish more sharply perceives bright light. Nervous by nature, during the period of illness they are more excitable and look for a secluded, dark place in which you can retire and calmly endure the disease. Help them - turn off any lighting - external (lamps for light and heating) and internal (color LED lamps). If a lot of light from outside comes into the aquarium itself, it is better to cover it with a sheet or thin blanket. The calmer the fish will feel, the closer the recovery.

    Third - no feed! From the word "completely"! Many breeders and just amateurs made this fatal mistake - they fed fish during treatment, arguing that "well, it's a pity they asked." Remember once and for all - the fish’s body is designed so that if it cannot find food in its natural habitat, it begins to digest its own organism. First of all, unhealthy parts of the body. Thus, the fish fights diseases and obesity in nature. If you continue to feed - it will be more difficult for her to cope with the disease, and subsequently lead to death.

    The golden rule of any aquarist is that the more hungry a fish is, the healthier it is! Without food, the fish lives, without any damage to the body, 21 days! So do not be afraid.

    For the period of the disease, it is not worth disconnecting the filtering and aeration of the aquarium. The continued availability of oxygen is crucial. Also, it would be very good to replace 1/5 of the aquarium water with fresh daily. This can be compared to airing in the patient's room.

    So, salt is added, the light is off, the feed is removed away. The first "emergency" help to your pets you have provided. In more detail each fish disease and methods of treating a specific disease will be discussed in the following articles.

    What fish diseases exist?

    Diseases of aquarium fish can be divided into several types:

    • Infectious diseases of fish caused by fungi, viruses, bacteria.
    • Diseases of physical and chemical origin.
    • Ailments due to poor nutrition, poor aquarium care.
    • Diseases of fish are invasive.

    Watch the video about the worst diseases.

    Variety of diseases

    Diseases of fish that are not transmitted to other animals:

    • Alkaline disease of aquarium inhabitants results from too soft alkaline balance of water. With excess light, a large number of plants, the water begins to sour, which becomes the cause of infection with alkalosis.
      The first symptoms of the disease are loss of color of the scales, fins spread wide, a large amount of bloody mucus is released from the gills. When moving, animals have a cramp. They jump out of the tank.
      With the advanced course of the disease, the optic cornea becomes turbid in animals, which subsequently leads to blindness. Aquarium fish most often die, it happens at night.
      You can get rid of the disease by transplanting animals into a container of water, the alkalinity of which is in the range of 7-8.5. At this time, the desired balance of acidity in the common tank should be established.
    • Argulez or "fish louse." The disease is caused by a parasite - crustacean carnivore. Symptoms of the disease are swollen wounds with red scales inflamed along the edges of which mucus constantly oozes. This happens due to the introduction of the parasite into the tissue. The fish stops eating. In an affected place, it constantly itches on solid decorations. Once inside the fish, the crustacean constantly releases a substance that leads to poisoning of the animal.
      In order to cure an individual, a crustacean should be removed from it. To do this, they catch it, wrap it with a soft cloth and use a pair of tweezers to pull out the parasitic crustacean. The affected area is treated with a solution of potassium permanganate.

    • Choking occurs due to the habitat of animals in the tank, poorly saturated with oxygen. The first signs are the opening of gill organs, a diseased fish swims near the surface.
      The first step on how to treat fish is to transplant them into a container with a good aeration system. At the same time, an oxygen balance is established in the common tank, spring cleaning is carried out, food residues are removed and the soil is siphoned.
      Symptoms are similar to some types of infectious diseases. At home, a diagnostic procedure is possible by normalizing the oxygen balance. If the animals recover, it means that they suffered from asphyxia.
    • Ammonia poisoning occurs as a result of oversaturation of the aquarium with plants, invertebrate species of animals, as well as due to the accumulation of a large amount of fish waste. External signs of the disease are changes in the color of the scales to a darker one. In this case, the fish swim close to the surface of the tank, often they try to jump out of it.
      Of the therapeutic actions, the first thing to do is to change 50% of the water, reduce the concentration of ammonia and nitrates and normalize the filtration, thoroughly clean the aquarium of debris and food debris.
    • An acid illness results in a decrease in pH due to the spawning period of fish or the emergence of new animals. You can understand the presence of the disease by lethargy and alertness of individuals, white spots, mucus appear on the scales. The movements of the fish become chaotic, they swim sideways or upside down.
      Aquarium fish are treated with baking soda, which is dissolved in water to normalize acid balance. Water is also partially replaced by fresh.

    • Problems with the stomach or intestines often arise due to poor quality food, when there is only one type of food in the diet of animals. The brightness of the color is lost, the fish do not move much. Feces with bloody impurities appear, the anal passage is inflamed.
      Aquarium fish treatment is carried out using fasting. For several days they are not fed at all, then a quality food suitable for the given species is gradually introduced.
    • The formation of cysts of the gonads is possible in the case of separately keeping males and females, as well as due to poor nutrition. The abdomen of aquarium fish swells due to the formation of a semi-fluid tumor. She begins to put pressure on all organs. Fish stop eating, become barren, and eventually die. Unfortunately, their treatment is almost impossible. This is due to the fact that it is difficult to recognize the disease in the first stages, and when it is already visible, it is too late to conduct therapy.
    • Dry and uniform food, overpopulation of the aquarium leads to obesity in fish. This can be understood by a sluggish lifestyle, a swollen upper abdomen.
      It is rare to cure obesity, most often the fish dies. Therefore, it is necessary to control the quality of the feed, the amount of feed, arrange fasting days for animals.

    • Chlorine poisoning is possible when replacing water, if you take it from the water supply and do not defend it in advance. Animals in this case swim in jerks, trying to jump out of the aquarium, spend most of the time at the surface of the water. Over time, they cease to respond to stimuli and die.
      Transplant animals into a chlorine-free water tank, and normalize the concentration of chlorine in the tank. You can just leave it for two days, most of the substance will disappear during this time. You can quickly get rid of the problem by heating the water to 90 degrees.
    • Colds are signs of an improper temperature balance; the water for this type of fish is too cold. You can understand this by the sluggish and swaying movements of animals, the scales darken, and the gills become dark. To get rid of the problem, it is enough to raise the temperature in the aquarium to the optimum for the fish of this species.

    Diseases transmitted to other animals

    • The cause of the appearance of white skin is bacteria. It enters the tank with new animals, decorations or vegetation. The dorsal and caudal fins become white, the fish is constantly located at the surface of the water. The causative agent bacteria affects the central nervous system, coordination. Possible death of the animal.
      They treat with chloramphenicol, making baths with medicine.
    • Branchiomycosis is caused by fungi that contribute to the appearance of blood clots in the vessels. Red spots appear on the body of the fish. She becomes inactive, stops eating, constantly hides in secluded darkened places. Over time, the tissues on the gills die.
      Animals can be saved if the diagnosis was made in the early stages, otherwise mass death of fish is possible. At the first sign of a sick pet, it is necessary to set it off, disinfect the general aquarium or restart the restart.

    • Hexamitosis occurs due to the parasite of the flagellum in the form of a drop. It leads to exhaustion of the individual, inflammation of the anus, the appearance of feces of white color. Small sores appear on the body. A sick animal quickly infects other fish, so it should immediately be deposited.
      Antibiotics are necessary medications for treatment. They are dissolved in water. In this case, it is necessary to control the nutrition of animals. Food should be varied and contain a large amount of nutrients.
    • Kostiosis is caused by invasion. It enters the tank with infected animals and plants, with live feed. Symptoms begin with the fact that the fish rub against objects in a container. Then the gills are covered with mucus, which leads to shortness of breath, and eventually to a complete stop.
      A sick fish is deposited and treated with the help of baths with a solution of potassium permanganate (a tenth of a gram per liter of water) or a solution of salt (a tablespoon of 10 liters).

    • Dactylogyrosis is caused by parasitic flukes that infect the gills of an animal. It stops eating, rubs against solid objects, eagerly captures air from the surface of the water. Gills become variegated, mucus appears.
      Parasites are excreted after increasing the temperature of the water, adding sodium chloride or bicillin to it.
    • Dermatomycosis occurs due to mold. It can cause damage not only to the skin, but also to internal organs. Diagnosis of aquarium fish diseases for the presence of fungus can be done by inspection. The body of the fish is covered with white threads. At first, organs cease to work, animals then die.
      The fungus is a secondary symptom of the underlying disease, so it should be treated. If the appearance is caused by a weakened immunity, add a solution of malachite green, potassium permanganate or food tar to the water.
    • Ichthyosporidiosis caused by a fungus kills all tissues except cartilage and bone. The fish itches, moves with jerks, refuses food, the eyes bulge out, wounds, tumors appear.

    There are no medicines to cure than animals. It dies, while infecting the remaining individuals. They should be destroyed. Restarting the aquarium after fish disease is possible only after disinfection of the tank.


    Preventing the onset of disease is easier than managing its consequences. Therefore, compliance with preventive measures is an important step in starting up and maintaining a tank:

    • Transport fish from the pet store correctly. To do this, use special bags in the warm season, and thermoses in the winter.
    • If you buy new animals in an existing tank, keep them several days in a separate container. Use water from the aquarium.
    • At the first sign of fish disease, drop them in a separate container.
    • Do not use aquarium equipment for healthy and diseased fish at the same time.
    • Regularly clean the container.
    • Replace a quarter of the volume of water every 10 days.

    Watch the video of changing the water in the aquarium.

    • Keep track of the number of animals in the aquarium, do not allow overpopulation.
    • Do not fill the tank with decorations of dubious quality, with a lot of dye that is released into the water.
    • Avoid ornaments with sharp edges; they can injure fish.
    • Buy high-quality food designed for the species of animals that live in the tank. Observe the correct storage method.
    • Watch your feeding schedule. You can arrange fasting days for fish only once a week. Do not overfeed animals.
    • Observe the temperature, alkaline, acid balance of the aquarium. To do this, use a water thermometer and special indicator strips.
    • When using medications to treat and prevent fish diseases, strictly follow the recommended dosage.

    Knowing the aquarium fish disease can prevent the death of the entire tank.

    Video about aquarium fish diseases and their treatment

    Chlorine poisoning

    The causes of the disease may be chemical factors (exposure to chlorine).The main symptoms are shortness of breath, the gills are covered with mucus and their color becomes lighter. Fish behave uneasily, rushing around and trying to jump out of the pool. Over time, they become lethargic, do not respond to anything, and die quickly.

    In order to prevent such a disease, it is necessary to constantly check the level of chlorine in the water. If there are signs of ailments in the fish, then they urgently need to be transplanted into clean water.

    Lack of oxygen

    Fish behave uneasily, swim near the surface and capture oxygen. One sign of a lack of air is the behavior of snails, which also raise to the surface. With a lack of oxygen in aquarium fish, weakening of immunity, infertility, suffocation, loss of appetite occurs, which leads to death.

    It is necessary to install aeration equipment in the aquarium. Periodically check the filter, aerator and oxygen circulation.

    Non-compliance with temperature conditions

    Occurs at elevated or reduced temperature in the aquarium. If the temperature is higher than necessary, then the fish are too active. They collect near the surface of the water due to a lack of oxygen. As a result, they experience oxygen starvation and exhaustion.

    Too low temperature is manifested in slow movements of fish, which are constantly at the bottom almost motionless. A long stay in cold water leads to colds and possible death. Therefore, it is necessary to constantly monitor the temperature controller and thermometer when changing water.

    A wide range of temperatures is well tolerated by some species: neon, goldfish, guppies and others.

    Alkaline disease (acidosis, alkalosis)

    The disease is promoted by an increased (alkalosis) or decreased (acidosis) alkali content in the water. With alkalosis, the behavior of aquarium fish becomes active, the gills and fins spread out, the color brightens. Mucus appears on the gills.

    Signs of acidosis: fish become shy, less active and mobile. Can swim belly up or sideways. Alkaline disease affects mainly those species of fish that are badly affected by changes in the acid-base balance (guppies, goldfish, neons, swordsmen). It can cause splitting of the fins, leading to death.

    The treatment consists in a gradual change in the level of alkali in the aquarium; it is brought to a neutral value. If the balance was abrupt, then the fish should be transplanted into clean water and the alkalinity level should be balanced.

    Fish obesity

    The disease occurs as a result of excess fat content by 3 percent in herbivorous fish and 5 percent in carnivores. With overfeeding, a monotonous diet or an unhealthy diet, symptoms of obesity can also occur.

    As a result of the disease, internal organs (liver, mesentery, kidneys) are affected. The fish becomes lethargic, her sides are rounded, infertility sets in, which leads to death.

    To prevent obesity, it is necessary to give various types of feed, fatty foods with a high protein content, ballast substances and for prevention do not feed a couple of days. The size of the aquarium should allow the fish to swim actively.

    Gas embolism

    It appears if the oxygen volume is exceeded, clogging of blood vessels in fish, impaired blood circulation. Therefore, it is necessary to monitor them and the condition of the aquarium. The behavior of fish is hectic, they begin to swim on their sides, gill covers are motionless.

    The appearance of small air bubbles on the walls, plants and soil indicates the occurrence of the disease. Bubbles can be on the fish itself and affect the internal organs. If they accumulate in the blood vessels, an embolism occurs and the fish die.

    In this case, they check how air circulates and the presence of excess plants, which contribute to the release of excessive oxygen and soil contamination.

    Infectious diseases of aquarium fish


    With this disease in aquarium fish, a change in appearance occurs - the color of the skin becomes lighter or white. Fish begin to swim on the surface. The causative agent is the bacterium Pseudomonas dermoalba, which can enter the aquarium with plants or infected fish.

    To treat the disease, the fish is placed in a container in which a solution of chloramphenicol is diluted. Soil and water in the aquarium are disinfected.

    Fin rot

    The most common aquarium fish disease. Appears as a result of damage to the fins due to poor water quality or bites of other fish. The fins are deformed, reduced in size, become a lighter shade. May accompany bacterial disease, while the body is covered with ulcers, the abdomen swells. Pseudomonas bacteria cause the disease.

    Treatment: poor-quality water should be changed, the aquarium and plants should be disinfected. Sick fish are placed in a container with a solution of chloramphenicol. It is better not to contain incompatible fish behavior. So, swordsmen are incompatible with aggressive large fish, etc.


    Mostly viviparous species of aquarium fish suffer from the disease: swordsmen, labyrinths, gourami. Their behavior changes - orientation is lost, there is a loss of appetite, they become lethargic, lethargic. In some species, abscesses, ulcers appear on the body, buccal eyes appear, others blind, the skin on them is covered with black dots, bones may appear.

    Cure is possible at an early stage of the disease, for which copper sulfate, tripoflavin, monocycline are used.

    Neon disease (Plistiforosis)

    The causative agent of the disease is an amoeba-shaped sporovic. Symptoms of the disease: movements become spasmodic, fish rise to the surface of the aquarium, body position upside down. Coordination is impaired, loss of appetite is observed, skin color fades. The fish keeps aloof, avoids flocks. Representatives of cyprinids (barbs, neons, goldfish, etc.) are affected by the disease.

    Neon disease is practically untreatable, so you need to destroy the diseased fish and thoroughly clean the aquarium.

    There is also a pseudo-neon disease, which is treated with a bactopur solution (1 tablet in 50 liters of water).

    Hexamitosis (hole disease)

    The causative agent of the disease is the intestinal flagellum affects the intestines and gall bladder. The carriers are sick fish, sometimes the cause is poor quality water. Symptoms: loss of appetite, discoloration, the fish keeps solitary, the appearance of mucous secretions.

    The disease can be cured in the early stages. To treat aquarium fish, you need to slowly increase the water temperature to 33-35 degrees or dilute metronidazole in a container (250 mg per 10 liters of water).

    Peptic ulcer

    The disease is caused by bacteria (Pseudomonas fluorescens) that enter the aquarium with food or from sick fish. Symptoms of the disease are dark spots on the skin of the fish, they gradually turn into ulcers. There is a bulging eye, the abdomen increases, the scales are affected, the appetite disappears, the infection penetrates the body.

    Timely treatment is necessary, for which streptocide is used (1 tablet per 10 liters of water) or potassium permanganate.

    Invasive aquarium fish diseases


    One of the most dangerous and serious diseases of aquarium fish, it affects their entire body and is not amenable to treatment. Symptoms: fish swim on their sides, bloody and whitish cones appear on the body. The diseases are predominantly affected by carp-like fish species (neon, goldfish, and others).


    Transmitted with contaminated feed, plants or soil. Symptoms of the disease: the fish rub against the ground, stones, a light coating appears on the skin. Gills become lighter, become covered with mucus, fish lose their appetite, its breathing is more frequent.

    Treatment of aquarium fish is best done in the early stages. Sick fish are placed in a container with a high temperature of water (31 degrees), to which methylene or sodium chloride (20 g per 10 l) is added.


    The causative agent is Costia necatris flagellate, which enters the aquarium with plants, feed and soil. The skin of the diseased fish is covered with mucus, the affected areas gradually decompose. The color on the gills changes, the fins stick together. The fish periodically rises to the surface and swallows air.

    To treat the disease, the water in the aquarium is heated to 32-34 degrees, or the fish are removed into a container with a solution of methylene salt.